86 static inline struct anon_vma *anon_vma_alloc(void)  in anon_vma_alloc()
88 	struct anon_vma *anon_vma;  in anon_vma_alloc()  local
90 	anon_vma = kmem_cache_alloc(anon_vma_cachep, GFP_KERNEL);  in anon_vma_alloc()
91 	if (anon_vma) {  in anon_vma_alloc()
92 		atomic_set(&anon_vma->refcount, 1);  in anon_vma_alloc()
93 		anon_vma->degree = 1;	/* Reference for first vma */  in anon_vma_alloc()
94 		anon_vma->parent = anon_vma;  in anon_vma_alloc()
99 		anon_vma->root = anon_vma;  in anon_vma_alloc()
102 	return anon_vma;  in anon_vma_alloc()
105 static inline void anon_vma_free(struct anon_vma *anon_vma)  in anon_vma_free()  argument
107 	VM_BUG_ON(atomic_read(&anon_vma->refcount));  in anon_vma_free()
127 	if (rwsem_is_locked(&anon_vma->root->rwsem)) {  in anon_vma_free()
128 		anon_vma_lock_write(anon_vma);  in anon_vma_free()
129 		anon_vma_unlock_write(anon_vma);  in anon_vma_free()
132 	kmem_cache_free(anon_vma_cachep, anon_vma);  in anon_vma_free()
147 				struct anon_vma *anon_vma)  in anon_vma_chain_link()  argument
150 	avc->anon_vma = anon_vma;  in anon_vma_chain_link()
152 	anon_vma_interval_tree_insert(avc, &anon_vma->rb_root);  in anon_vma_chain_link()
186 	struct anon_vma *anon_vma, *allocated;  in __anon_vma_prepare()  local
195 	anon_vma = find_mergeable_anon_vma(vma);  in __anon_vma_prepare()
197 	if (!anon_vma) {  in __anon_vma_prepare()
198 		anon_vma = anon_vma_alloc();  in __anon_vma_prepare()
199 		if (unlikely(!anon_vma))  in __anon_vma_prepare()
201 		allocated = anon_vma;  in __anon_vma_prepare()
204 	anon_vma_lock_write(anon_vma);  in __anon_vma_prepare()
207 	if (likely(!vma->anon_vma)) {  in __anon_vma_prepare()
208 		vma->anon_vma = anon_vma;  in __anon_vma_prepare()
209 		anon_vma_chain_link(vma, avc, anon_vma);  in __anon_vma_prepare()
211 		anon_vma->degree++;  in __anon_vma_prepare()
216 	anon_vma_unlock_write(anon_vma);  in __anon_vma_prepare()
239 static inline struct anon_vma *lock_anon_vma_root(struct anon_vma *root, struct anon_vma *anon_vma)  in lock_anon_vma_root()  argument
241 	struct anon_vma *new_root = anon_vma->root;  in lock_anon_vma_root()
251 static inline void unlock_anon_vma_root(struct anon_vma *root)  in unlock_anon_vma_root()
278 	struct anon_vma *root = NULL;  in anon_vma_clone()
281 		struct anon_vma *anon_vma;  in anon_vma_clone()  local
291 		anon_vma = pavc->anon_vma;  in anon_vma_clone()
292 		root = lock_anon_vma_root(root, anon_vma);  in anon_vma_clone()
293 		anon_vma_chain_link(dst, avc, anon_vma);  in anon_vma_clone()
303 		if (!dst->anon_vma && src->anon_vma &&  in anon_vma_clone()
304 		    anon_vma != src->anon_vma && anon_vma->degree < 2)  in anon_vma_clone()
305 			dst->anon_vma = anon_vma;  in anon_vma_clone()
307 	if (dst->anon_vma)  in anon_vma_clone()
308 		dst->anon_vma->degree++;  in anon_vma_clone()
319 	dst->anon_vma = NULL;  in anon_vma_clone()
332 	struct anon_vma *anon_vma;  in anon_vma_fork()  local
336 	if (!pvma->anon_vma)  in anon_vma_fork()
340 	vma->anon_vma = NULL;  in anon_vma_fork()
351 	if (vma->anon_vma)  in anon_vma_fork()
355 	anon_vma = anon_vma_alloc();  in anon_vma_fork()
356 	if (!anon_vma)  in anon_vma_fork()
366 	anon_vma->root = pvma->anon_vma->root;  in anon_vma_fork()
367 	anon_vma->parent = pvma->anon_vma;  in anon_vma_fork()
373 	get_anon_vma(anon_vma->root);  in anon_vma_fork()
375 	vma->anon_vma = anon_vma;  in anon_vma_fork()
376 	anon_vma_lock_write(anon_vma);  in anon_vma_fork()
377 	anon_vma_chain_link(vma, avc, anon_vma);  in anon_vma_fork()
378 	anon_vma->parent->degree++;  in anon_vma_fork()
379 	anon_vma_unlock_write(anon_vma);  in anon_vma_fork()
384 	put_anon_vma(anon_vma);  in anon_vma_fork()
393 	struct anon_vma *root = NULL;  in unlink_anon_vmas()
400 		struct anon_vma *anon_vma = avc->anon_vma;  in unlink_anon_vmas()  local
402 		root = lock_anon_vma_root(root, anon_vma);  in unlink_anon_vmas()
403 		anon_vma_interval_tree_remove(avc, &anon_vma->rb_root);  in unlink_anon_vmas()
409 		if (RB_EMPTY_ROOT(&anon_vma->rb_root.rb_root)) {  in unlink_anon_vmas()
410 			anon_vma->parent->degree--;  in unlink_anon_vmas()
417 	if (vma->anon_vma) {  in unlink_anon_vmas()
418 		vma->anon_vma->degree--;  in unlink_anon_vmas()
424 		vma->anon_vma = NULL;  in unlink_anon_vmas()
434 		struct anon_vma *anon_vma = avc->anon_vma;  in unlink_anon_vmas()  local
436 		VM_WARN_ON(anon_vma->degree);  in unlink_anon_vmas()
437 		put_anon_vma(anon_vma);  in unlink_anon_vmas()
446 	struct anon_vma *anon_vma = data;  in anon_vma_ctor()  local
448 	init_rwsem(&anon_vma->rwsem);  in anon_vma_ctor()
449 	atomic_set(&anon_vma->refcount, 0);  in anon_vma_ctor()
450 	anon_vma->rb_root = RB_ROOT_CACHED;  in anon_vma_ctor()
455 	anon_vma_cachep = kmem_cache_create("anon_vma", sizeof(struct anon_vma),  in anon_vma_init()
486 struct anon_vma *page_get_anon_vma(struct page *page)  in page_get_anon_vma()
488 	struct anon_vma *anon_vma = NULL;  in page_get_anon_vma()  local
498 	anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);  in page_get_anon_vma()
499 	if (!atomic_inc_not_zero(&anon_vma->refcount)) {  in page_get_anon_vma()
500 		anon_vma = NULL;  in page_get_anon_vma()
513 		put_anon_vma(anon_vma);  in page_get_anon_vma()
519 	return anon_vma;  in page_get_anon_vma()
529 struct anon_vma *page_lock_anon_vma_read(struct page *page)  in page_lock_anon_vma_read()
531 	struct anon_vma *anon_vma = NULL;  in page_lock_anon_vma_read()  local
532 	struct anon_vma *root_anon_vma;  in page_lock_anon_vma_read()
542 	anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);  in page_lock_anon_vma_read()
543 	root_anon_vma = READ_ONCE(anon_vma->root);  in page_lock_anon_vma_read()
552 			anon_vma = NULL;  in page_lock_anon_vma_read()
558 	if (!atomic_inc_not_zero(&anon_vma->refcount)) {  in page_lock_anon_vma_read()
559 		anon_vma = NULL;  in page_lock_anon_vma_read()
565 		put_anon_vma(anon_vma);  in page_lock_anon_vma_read()
571 	anon_vma_lock_read(anon_vma);  in page_lock_anon_vma_read()
573 	if (atomic_dec_and_test(&anon_vma->refcount)) {  in page_lock_anon_vma_read()
579 		anon_vma_unlock_read(anon_vma);  in page_lock_anon_vma_read()
580 		__put_anon_vma(anon_vma);  in page_lock_anon_vma_read()
581 		anon_vma = NULL;  in page_lock_anon_vma_read()
584 	return anon_vma;  in page_lock_anon_vma_read()
588 	return anon_vma;  in page_lock_anon_vma_read()
591 void page_unlock_anon_vma_read(struct anon_vma *anon_vma)  in page_unlock_anon_vma_read()  argument
593 	anon_vma_unlock_read(anon_vma);  in page_unlock_anon_vma_read()
712 		struct anon_vma *page__anon_vma = page_anon_vma(page);  in page_address_in_vma()
717 		if (!vma->anon_vma || !page__anon_vma ||  in page_address_in_vma()
718 		    vma->anon_vma->root != page__anon_vma->root)  in page_address_in_vma()
1021 	struct anon_vma *anon_vma = vma->anon_vma;  in page_move_anon_rmap()  local
1026 	VM_BUG_ON_VMA(!anon_vma, vma);  in page_move_anon_rmap()
1028 	anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;  in page_move_anon_rmap()
1034 	WRITE_ONCE(page->mapping, (struct address_space *) anon_vma);  in page_move_anon_rmap()
1047 	struct anon_vma *anon_vma = vma->anon_vma;  in __page_set_anon_rmap()  local
1049 	BUG_ON(!anon_vma);  in __page_set_anon_rmap()
1060 		anon_vma = anon_vma->root;  in __page_set_anon_rmap()
1068 	anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;  in __page_set_anon_rmap()
1069 	WRITE_ONCE(page->mapping, (struct address_space *) anon_vma);  in __page_set_anon_rmap()
1093 	VM_BUG_ON_PAGE(page_anon_vma(page)->root != vma->anon_vma->root, page);  in __page_check_anon_rmap()
2222 void __put_anon_vma(struct anon_vma *anon_vma)  in __put_anon_vma()  argument
2224 	struct anon_vma *root = anon_vma->root;  in __put_anon_vma()
2226 	anon_vma_free(anon_vma);  in __put_anon_vma()
2227 	if (root != anon_vma && atomic_dec_and_test(&root->refcount))  in __put_anon_vma()
2231 static struct anon_vma *rmap_walk_anon_lock(struct page *page,  in rmap_walk_anon_lock()
2234 	struct anon_vma *anon_vma;  in rmap_walk_anon_lock()  local
2245 	anon_vma = page_anon_vma(page);  in rmap_walk_anon_lock()
2246 	if (!anon_vma)  in rmap_walk_anon_lock()
2249 	anon_vma_lock_read(anon_vma);  in rmap_walk_anon_lock()
2250 	return anon_vma;  in rmap_walk_anon_lock()
2270 	struct anon_vma *anon_vma;  in rmap_walk_anon()  local
2275 		anon_vma = page_anon_vma(page);  in rmap_walk_anon()
2277 		VM_BUG_ON_PAGE(!anon_vma, page);  in rmap_walk_anon()
2279 		anon_vma = rmap_walk_anon_lock(page, rwc);  in rmap_walk_anon()
2281 	if (!anon_vma)  in rmap_walk_anon()
2286 	anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root,  in rmap_walk_anon()
2304 		anon_vma_unlock_read(anon_vma);  in rmap_walk_anon()
2393 	struct anon_vma *anon_vma = vma->anon_vma;  in hugepage_add_anon_rmap()  local
2397 	BUG_ON(!anon_vma);  in hugepage_add_anon_rmap()